This invention relates generally to power feeding of strip material and more particularly, relates to a novel machine for straightening the camber of strip steel or like material being power fed to metal working equipment, such as punch presses.
An automatic or other press, such as a punch press, often is continuously supplied with strip material, such as steel, to mass produce one piece part. The press is provided with a die which punches the same part from the web of strip steel as the web is fed through the press. The web of strip steel usually is fed to the press from a power driven coil of the material obtained from a supplier. The power driving mechanism rotates the coil for unwinding the strip material for feeding to the press.
This strip material coming off the coil's circumference frequently has a camber which hampers or even prevents the power feeding of the strip material from the coil to the press. Camber is that condition of strip material wherein the strip material will curve to the right or left when placed on a planar surface. Camber is defined as the deviation of a side edge of the material from a straight line and may be measured by placing an eight foot straight edge against the concave edge of the material. The distance between the straight edge and concave edge of the material is the quantified camber of the material.
Some camber can be tolerated by the die of a punch press. Many times, however, the camber of the strip material is great enough to prevent the material from entering the die or cause jamming of the material entering the die. This results in material that cannot be used for its intended application; such material must be scrapped, often at a substantial monetary loss.
The invention herein provides a novel machine constructed to remove or reduce the camber of the strip material concurrently with the strip material being fed to the die of the press. The machine of the present invention is located between the coil and the press. The cambered strip material is power fed through the machine and has its camber removed or reduced to an acceptable degree before entering the punch press, for instance. The strip material which exits from the machine thus is in a condition which is readily useable by the press die.
Other devices for straightening elongate materials are known. For example, U.S. Pat. No. 2,492,491 discloses a pipe bending vice; U.S. Pat. No. 2,278,353 discloses a rod straightener; and U.S. Pat. No. 2,232,724 discloses a rail bender. In these patents, elongate materials, such as pipe, rod and railroad rails, are bent or straightened. The devices disclosed perform the bending or straightening by applying a force to the material between two fixed supports.
However, all of these devices provide for stationary and intermitent operation. The material to be bent or straightened is not continuously passed through the device. U.S. Pat. No. 2,492,491 provides a device which grips the pipe stationary in a vise for bending at individual locations. U.S. Pat. No. 2,278,353 provides a device where a shaft of a farm machine may be straightened without removing the shaft from the machine. U.S. Pat. No. 3,232,724 provides a rail straightener with jaws engaging the rail to prevent breakage of the straightener. All of these devices provide for holding the material stationary while the material is bent or straightened at individual locations.
The machine embodying the invention operates to continuously remove camber from a web of strip metal along the entire length of the web concurrently with the strip material passing through the machine. The strip material is not successively straightened at individual adjacent sections as it is fed to the press; rather it is continuously straightened concurrently with its being fed to the press. This provides for desirable continuous feeding of camber straightened strip material to the press so that an uninterrupted, rapid rate of stamping of parts can be maintained.
The machine embodying the invention further is provided with bearing members which are replaceable. Thus, an inexpensive base made of a soft metal may be used which need not be replaced due to wear caused by hard or hardened strip material.
The machine embodying the invention is portable and uncomplicated and is adjusted easily for different widths and heights of strip material and for different amounts of camber.